Material Properties of TiO2 Nanotube Arrays: Structural, Elemental, Mechanical, Optical and Electrical



In this chapter, we examine the structural, elemental, crystallization, optical, electrical, and mechanical properties of the anodization-synthesized titania nanotube arrays.

It is known that the as-fabricated nanotube arrays have an amorphous crystallographic structure. Upon annealing at elevated temperatures in an oxygen ambient, the nanotube walls transform into anatase phase, and a layer of metal underneath the nanotubes converts into rutile [1–9]; the observed crystalline phases are polycrystalline. We make note of a publication where the authors mistook the diffraction pattern of a selected small area, determined using transmission electron microscopy (TEM), as representing a single-crystal nanotube [10]. Titania properties depend on the crystallinity and isomorph type, and hence the utility of their application also varies. For example, anatase phase is preferred in charge-separating devices such as dye-sensitized solar cells (DSCs) and in photocatalysis, while rutile is used predominantly in gas sensors and as dielectric layers. Of the titania polymorphs, rutile has minimum free energy, and hence given the necessary activation energy, other polymorphs including anatase transform into rutile through a first-order phase transformation. The temperature at which metastable anatase converts to rutile depends upon several factors including the presence of impurities, feature size, texture, and strain. Hence with sintering, porosity and/or surface area reduction occur due to nucleation-growth type of phase transformations [11–13].


Barrier Layer Anatase Phase Flat Band Potential Barrier Layer Thickness Schottky Plot 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Varghese OK, Gong D, Paulose M, Ong KG, Grimes CA, Dickey EC (2003) Crystallization and high-temperature structural stability of titanium oxide nanotube arrays. J Mater Res 18:156–165Google Scholar
  2. 2.
    Cai Q, Paulose M, Varghese OK, Grimes CA (2005) The effect of electrolyte composition on the fabrication of self-organized titanium oxide nanotube arrays by anodic oxidation. J Mater Res 20:230–236Google Scholar
  3. 3.
    Mor GK, Varghese OK, Paulose M, Grimes CA (2005) Transparent highly ordered TiO2 nanotube arrays via anodization of titanium thin films. Adv Funct Mater 15:1291–1296Google Scholar
  4. 4.
    Mor GK, Varghese OK, Paulose M, Shankar K, Grimes CA (2006) A review on highly ordered, vertically oriented TiO2 nanotube arrays: fabrication, material properties, and solar energy applications. Sol Energy Mater Sol Cells 90:2011–2075Google Scholar
  5. 5.
    Zhao J, Wang X, Sun T, Li L (2005) In situ templated synthesis of anatase single-crystal nanotube arrays. Nanotechnol 16:2450–2454Google Scholar
  6. 6.
    Ghicov A, Tsuchiya H, Macak JM, Schmuki P (2006) Annealing effects on the photoresponse of TiO2 nanotubes. Phys Stat Sol 203:R28–R30Google Scholar
  7. 7.
    Hahn R, Ghicov A, Salonen J, Lehto VP, Schmuki P (2007) Carbon doping of self-organized TiO2 nanotube layers by thermal acetylene treatment. Nanotechnol 18:105604 (4pp)Google Scholar
  8. 8.
    Macak JM, Ghicov A, Hahn R, Tsuchiya H, Schmuki P (2006) Photoelectrochemical properties of N-doped self-organized titania nanotube layers with different thicknesses. J Mater Res 21:2824–2828Google Scholar
  9. 9.
    Yang Y, Wang X, Li L (2008) Crystallization and phase transition of titanium oxide nanotube arrays. J Am Ceram Soc 91:632–635Google Scholar
  10. 10.
    Zhao J, Wang X, Sun T, Li L (2007) Crystal phase transition and properties of titanium oxide nanotube arrays prepared by anodization. J Alloys Compd 434–435:792–795Google Scholar
  11. 11.
    Whittemore OJ, Sipe JJ (1974) Pore growth during initial stages of sintering ceramics. Powder Technol 9:159–164Google Scholar
  12. 12.
    Kumar KNP, Keizer K, Burggraaf AJ (1993) Textural evolution and phase-transformation in titania membranes 1. Unsupported membranes. J Mater Chem 3:1141–1149Google Scholar
  13. 13.
    Kumar KNP, Keizer K, Burggraaf AJ, Okubo T, Nagamoto H (1993) Textural evolution and phase-transformation in titania membranes 2. Supported membranes. J Mater Chem 3:1151–1159Google Scholar
  14. 14.
    Macak JM, Tsuchiya H, Schmuki P (2005) High-aspect-ratio TiO2 nanotubes by anodization of titanium. Angew Chem Int Ed 44:2100–2102Google Scholar
  15. 15.
    Cullity BD, Stock SR (2001) Elements of X-ray diffraction. Prentice-Hall, Englewood Cliffs, NJGoogle Scholar
  16. 16.
    Lai Y, Sun L, Chen Y, Zhuang H, Lin C, Chin JW (2006) Effects of the structure of TiO2 nanotube array on Ti substrate on its photocatalytic activity. J Electrochem Soc 153:D123–D127Google Scholar
  17. 17.
    Chastain J (1992) Handbook of X-ray photoelectron spectroscopy. Perkin-Elmer, Eden Prairie, MNGoogle Scholar
  18. 18.
    McCafferty E, Wightman JP (1998) Determination of the concentration of surface hydroxyl groups on metal oxide films by a quantitative XPS method. Surf Interface Anal 26:549–564Google Scholar
  19. 19.
    Saha NC, Tomkins HC (1992) Titanium nitride oxidation chemistry – an X-ray photoelectron-spectroscopy study. J Appl Phys 72:3072–3079Google Scholar
  20. 20.
    Marino CEB, Nascente PAP, Biaggio SR, Rocha-Filho RC, Bocchi N (2004) XPS characterization of anodic titanium oxide films grown in phosphate buffer solutions. Thin Solid Films 468:109–112Google Scholar
  21. 21.
    Varghese OK, Paulose M, Shankar K, Mor GK, Grimes CA (2005) Water-photolysis properties of micron-length highly-ordered titania nanotube-arrays. J Nanosci Nanotechnol 5:1158–1165Google Scholar
  22. 22.
    Paulose M, Mor GK, Varghese OK, Shankar K, Grimes CA (2006) Visible light photoelectrochemical and water-photoelectrolysis properties of titania nanotube arrays. J Photochem Photobiol A 178:8–15Google Scholar
  23. 23.
    Ohya Y, Saiki H, Tanaka T, Takahashi Y (1996) Microstructure of TiO2 and ZnO films fabricated by the sol-gel method. J Am Ceram Soc 79:825–830Google Scholar
  24. 24.
    Shankar K, Mor GK, Prakasam HE, Yoriya S, Paulose M, Varghese OK, Grimes CA (2007) Highly-ordered TiO2 nanotube-arrays up to 220 µm in length: use in water photoelectrolysis and dye-sensitized solar cells. Nanotechnol18:065707 (11pp)Google Scholar
  25. 25.
    Yoriya S, Prakasam HE, Varghese OK, Shankar K, Paulose M, Mor GK, Latempa TA, Grimes CA (2006) Initial studies on the hydrogen gas sensing properties of highly-ordered high aspect ratio TiO2 nanotube-arrays 20 μm to 222 μm in length. Sens Lett 4:334–339Google Scholar
  26. 26.
    Allam NK, Shankar K, Grimes CA (2008) General method for the anodic formation of crystalline metal oxide nanotube arrays without the use of thermal annealing. Adv Mater 20:3942–3946Google Scholar
  27. 27.
    Nishikiori H, Qian W, El-Sayed MA, Tanaka N, Fujii T (2007) Change in titania structure from amorphousness to crystalline increasing photoinduced electron-transfer rate in dye-titania system. J Phys Chem C 111:9008–9011Google Scholar
  28. 28.
    Kondo JN, Domen K (2008) Crystallization of mesoporous metal oxides. Chem Mat 20: 835–847Google Scholar
  29. 29.
    Grimes CA (2007) Synthesis and application of highly ordered arrays of TiO2 nanotubes. J Mat Chem 17:1451–1457Google Scholar
  30. 30.
    Lee J, Orilall MC, Warren SC, Kamperman M, Disalvo FJ, Wiesner U (2008) Direct access to thermally stable and highly crystalline mesoporous transition-metal oxides with uniform pores. Nature Mater 7:222–228Google Scholar
  31. 31.
    Ohtani B, Ogawa Y, Nishimoto S (1997) Photocatalytic activity of amorphous-anatase mixture of titanium (IV) oxide particles suspended in aqueous solutions. J Phys Chem B 101:3746–3752Google Scholar
  32. 32.
    Demazeau G (2008) Solvothermal reactions: an original route for the synthesis of novel materials. J Mater Sci 43:2104–2114Google Scholar
  33. 33.
    Cushing BL, Kolesnichenko VL, O’Connor CJ (2004) Recent advances in the liquid-phase syntheses of inorganic nanoparticles. Chem Rev 104:3893–3946Google Scholar
  34. 34.
    Roy R (1994) Accelerating the kinetics of low-temperature inorganic syntheses. J Solid State Chem 111:11–17Google Scholar
  35. 35.
    Walton RI (2002) Subcritical solvothermal synthesis of condensed inorganic materials. Chem Soc Rev 31:230–238Google Scholar
  36. 36.
    Mahltig B, Gutmann E, Meyer DC, Reibold M, Dresler B, Günther K, Faßler D, Böttcher H (2007) Solvothermal preparation of metallized titania sols for photocatalytic and antimicrobial coatings. J Mater Chem 17:2367–2374Google Scholar
  37. 37.
    Chen D, Jiao XF, Ritchie RO (2000) Effects of grain-boundary structure on the strength, toughness, and cyclic-fatigue properties of a monolithic silicon carbide. J Am Ceram Soc 83:2079–2081Google Scholar
  38. 38.
    Yoriya S, Mor GK, Sharma S, Grimes CA (2008) Synthesis of ordered arrays of discrete, partially crystalline titania nanotubes by Ti anodization using diethylene glycol electrolytes. J Mater Chem 18:3332–3336Google Scholar
  39. 39.
    Habazaki H, Shimizu K, Nagata S, Skeldon P, Thompson GE, Wood GC (2002) Ionic transport in amorphous anodic titania stabilised by incorporation of silicon species. Corros Sci 44:1047–1055Google Scholar
  40. 40.
    Habazaki H, Shimizu K, Nagata S, Skeldon P, Thompson GE (2007) Fast migration of fluoride ions in growing anodic titanium oxide. Electrochem Commun 9:1222–1227Google Scholar
  41. 41.
    Yu T, Bu H, Chen J (1986) The effect of units derived from diethylene glycol on crystallization kinetics of poly(ethylene terephthalate). Macromol Chem 187:2697–2709Google Scholar
  42. 42.
    Kinart CM, Cwiklinska A, Maj M, Kinart WJ (2007) Thermodynamic and physicochemical properties of binary mixtures of sulfolane with ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol systems at 303.15 K. Fluid Phase Equilib 262:244–250Google Scholar
  43. 43.
    Cocchi M, Marchetti A, Pigani L, Sanna G, Tassi L, Ulrici A, Vaccari G, Zanardi C (2000) Density and volumetric properties of ethane-1, 2-diol plus di-ethylene glycol mixtures at different temperatures. Fluid Phase Equilib 172:93–104Google Scholar
  44. 44.
    Mor GK, Shankar K, Paulose M, Varghese OK, Grimes CA (2005) Enhanced photocleavage of water using titania nanotube arrays. Nano Lett 5:191–195Google Scholar
  45. 45.
    Park JH, Kim S, Bard AJ (2006) Novel carbon-doped TiO2 nanotube arrays with high aspect ratios for efficient solar water splitting. Nano Lett 6:24–28Google Scholar
  46. 46.
    Raja KS, Misra M, Mahajan VK, Gandhi T, Pillai P, Mohapatra SK (2006) Photo-electrochemical hydrogen generation using band-gap modified nanotubular titanium oxide in solar light. J Power Sources 161:1450–1457Google Scholar
  47. 47.
    Paulose M, Shankar K, Yoriya S, Prakasam HE, Varghese OK, Mor GK, Latempa TJ, Fitzgerald A, Grimes CA (2006) Anodic growth of highly ordered TiO2 nanotube arrays to 134 μm in length. J Phys Chem B 110:16179–16184Google Scholar
  48. 48.
    Zhu K, Neale NR, Miedaner A, Frank AJ (2006) Enhanced charge-collection efficiencies and light scattering in dye-sensitized solar cells using oriented TiO2 nanotubes arrays. Nano Lett 7:69–74Google Scholar
  49. 49.
    Hahn R, Ghicov A, Salonen J, Lehto V, Schmuki P (2007) Carbon doping of self-organized TiO2 nanotube layers by thermal acetylene treatment. Nanotechnol 18:105604 (4pp)Google Scholar
  50. 50.
    Mohapatra SK, Misra M, Mahajan VK, Raja KS (2007) Design of a highly efficient photoelectrolytic cell for hydrogen generation by water splitting: application of TiO2-xCxnanotubes as a photoanode and Pt/TiO2 nanotubes as a cathode. J Phys Chem C 111: 8677–8685Google Scholar
  51. 51.
    Tang XH, Li DY (2008) Sulfur doped highly ordered TiO2 nanotubular arrays with visible light response. J Phys Chem C 112:5405–5409Google Scholar
  52. 52.
    Vitiello RP, Macak JM, Ghicov A, Tsuchiya H, Dick LFP, Schmuki P (2006) N-Doping of anodic TiO2 nanotubes using heat treatment in ammonia. Electrochem Commun 8:544–548Google Scholar
  53. 53.
    Lu N, Quan X, Li JY, Chen S, Yu HT, Chen GH (2007) Fabrication of boron-doped TiO2 nanotube array electrode and investigation of its photoelectrochemical capability. J Phys Chem C 111:11836–11842Google Scholar
  54. 54.
    Mohapatra SK, Misra M, Mahajan VK, Raja KS (2007) A novel method for the synthesis of titania nanotubes using sonoelectrochemical method and its application for photoelectrochemical splitting of water. J Catal 246:362–369Google Scholar
  55. 55.
    Shankar K, Paulose M, Mor GK, Varghese OK, Grimes CA (2005) A study on the spectral photoresponse and photoelectrochemical properties of flame-annealed titania nanotube arrays. J Phys D 38:3543–3549Google Scholar
  56. 56.
    Choi Y, Umebayashi T, Yamamoto S, Tanaka S (2003) Fabrication of TiO2 photocatalysts by oxidative annealing of TiC. J Mater Sci Lett 22:1209–1211Google Scholar
  57. 57.
    Asahi R, Morikawa T, Ohwaki T, Aoki K, Taga Y (2001) Visible-light photocatalysis in nitrogen-doped titanium oxides. Science 293:269–271Google Scholar
  58. 58.
    Lindgren T, Mwabora JM, Avendano E, Jonsson J, Hoel A, Granvist CG, Lindquist SE (2003) Photoelectrochemical and optical properties of nitrogen doped titanium dioxide films prepared by reactive DC magnetron sputtering. J Phys Chem B 107:5709–5716Google Scholar
  59. 59.
    Kosowska B, Mozia S, Morawski A, Grznil B, Janus M, Kalucki K (2005) The preparation of TiO2-nitrogen doped by calcination of TiO2 center dot xH(2) O under ammonia atmosphere for visible light photocatalysis. Sol Energy Mater Sol Cells 88:269–280Google Scholar
  60. 60.
    Wang Y, Feng C, Jin Z, Zhang J, Yang J, Zhang S (2006) A novel N-doped TiO2 with high visible light photocatalytic activity. J Mol Catal A 260:1–3Google Scholar
  61. 61.
    Ghicov A, Macak JM, Tsuchiya H, Kunze J, Haeublein V, Frey L, Schmuki P (2006) Ion implantation and annealing for an efficient N-doping of TiO2 nanotubes. Nano Lett 6:1080–1082Google Scholar
  62. 62.
    Ghicov A, Macak JM, Tsuchiya H, Kunze J, Haeublein V, Kleber S, Schmuki P (2006) TiO2 nanotube layers: dose effects during nitrogen doping by ion implantation. Chem Phys Lett 419:426–429Google Scholar
  63. 63.
    Shankar K, Tep KC, Mor GK, Grimes CA (2006) An electrochemical strategy to incorporate nitrogen in nanostructured TiO2 thin films: modification of bandgap and photoelectrochemical properties. J Phys D 39:2361–2366Google Scholar
  64. 64.
    Chourasia AR, Chopra DR (1992) X-ray photoelectron spectra of TiN. Surf Sci Spectra 1:233–237Google Scholar
  65. 65.
    Chourasia AR, Chopra DR (1995) X-ray photoelectron study of Tin/SiO2 and Tin/Si interfaces. Thin Solid Films 266:298–301Google Scholar
  66. 66.
    Yakovleva NM, Anicai L, Yakovlev AN, Dima L, Khanina EY, Buda M, Chupakhina EA (2002) Structural study of anodic films formed on aluminum in nitric acid electrolyte. Thin Solid Films 416:16–23Google Scholar
  67. 67.
    Augustynski J, Berthou H, Painot J (1976) XPS study of interactions between aluminum metal and nitrate ions. Chem Phys Lett 44:221–224Google Scholar
  68. 68.
    Parkhutik VP, Makushok YE, Kudryavtsev VI, Sokol VA, Khodan AN (1987) X-ray photoelectron study of the formation of anodic oxide-films on aluminum in nitric-acid. Sov Electrochem 23:1439–1444Google Scholar
  69. 69.
    Öchsner R, Kluge A, Ryssel H (1989) A versatile ion implanter for material modification. Nucl Instrum Methods B 37–38:504–507Google Scholar
  70. 70.
    Saha NC, Tompkins HG (1992) Titanium nitride oxidation chemistry – an X-ray photoelectron-spectroscopy study. J Appl Phys 72:3072–3079Google Scholar
  71. 71.
    Li J, Lu N, Quan X, Chen S, Zhao H (2008) Facile method for fabricating boron-doped TiO2 nanotube array with enhanced photoelectrocatalytic properties. Ind Eng Chem Res 47:3804–3808Google Scholar
  72. 72.
    Chen D, Yang D, Wang Q, Jiang ZY (2006) Effects of boron doping on photocatalytic activity and microstructure of titanium dioxide nanoparticles. Ind Eng Chem Res 45:4110–4116Google Scholar
  73. 73.
    Zhao W, Ma WH, Chen CC, Zhao JC, Shuai ZG (2004) Efficient degradation of toxic organic pollutants with Ni2O3/TiO2-xBxunder visible irradiation. J Am Chem Soc 126:4782–4783Google Scholar
  74. 74.
    Ruan C, Paulose M, Varghese OK, Mor GK, Grimes CA (2005) Fabrication of highly ordered TiO2 nanotube arrays using an organic electrolyte. J Phys Chem B 109:15754–15759Google Scholar
  75. 75.
    Chen SG, Paulose M, Ruan C, Mor GK, Varghese OK, Kouzoudis D, Grimes CA (2006) Electrochemically synthesized CdS nanoparticle-modified TiO2 nanotube-array photoelectrodes: preparation, characterization, and application to photoelectrochemical cells. J Photochem Photobiol 177:177–184Google Scholar
  76. 76.
    Kundu M, Khosravi AA, Kulkarni SK (1997) Synthesis and study of organically capped ultra small clusters of cadmium sulphide. J Mater Sci 32:245–258Google Scholar
  77. 77.
    Savelli M, Bougnot J (1979) Topics in applied physics, vol 31. Solar Energy Conversion, Springer, BerlinGoogle Scholar
  78. 78.
    Mor GK, Varghese OK, Paulose M, Shankar K, Grimes CA (2005) Effect of anodization bath chemistry on photochemical water splitting using titania nanotubes. Mater Res Soc Symp Proc 836:L1.9.1Google Scholar
  79. 79.
    de Taconni NR, Chenthamarakshan CR, Yogeeswaran G, Watcharenwong A, de Zoysa RS, Basit NA, Rajeshwar K (2006) Nanoporous TiO2 and WO3 films by anodization of titanium and tungsten substrates: Influence of process variables on morphology and photoelectrochemical response. J Phys Chem B 110:25347–25355Google Scholar
  80. 80.
    Taflove A (1995) Computational electrodynamics: the finite-difference time-domain method. Artech House Inc, BostonGoogle Scholar
  81. 81.
    Ong KG, Varghese OK, Mor GK, Grimes CA (2005) Numerical simulation of light propagation through highly-ordered titania nanotube arrays: Dimension optimization for improved photoabsorption. J Nanosci Nanotechnol 5:1–7Google Scholar
  82. 82.
    Roden JA, Gedney SD (1997) Efficient implementation of the uniaxial-based PML media in three-dimensional nonorthogonal coordinates with the use of the FDTD technique. Microwave Opt Technol Lett 14:71–75Google Scholar
  83. 83.
    Wittberg TN, Wolf JD, Keil RG, Wang PS (1983) Low-temperature oxygen diffusion in alpha titanium characterized by auger sputter profiling. J Vac Sci Technol A 1:475–478Google Scholar
  84. 84.
    Negishi N, Takeuchi K, Ibusuki T (1998) Surface structure of the TiO2 thin film photocatalyst. J Mater Sci 33:5789–5794Google Scholar
  85. 85.
    Amanullah FM, Al-Mobarak MS, Al-Dhafiri AM, Al-Shibani KM (1999) Development of spray technique for the preparation of thin films and characterization of tin oxide transparent conductors. Mater Chem Phys 59:247–253Google Scholar
  86. 86.
    Yang P, Liou KN, Mishchenko MI, Gao BC (2000) Efficient finite-difference time-domain scheme for light scattering by dielectric particles: application to aerosols. Appl Opt 39:3727–3737Google Scholar
  87. 87.
    Mor GK, Shankar K, Varghese OK, Grimes CA (2004) Photoelectrochemical properties of titania nanotubes. J Mater Res 19:2989–2996Google Scholar
  88. 88.
    Zheng S, Gao L, Zhang QH, Sun J (2001) Synthesis, characterization, and photoactivity of nanosized palladium clusters deposited on titania-modified mesoporous MCM-41. J Solid State Chem 162:138–141Google Scholar
  89. 89.
    Vogel R, Meredith P, Kartini I, Harvey M, Riches JD, Bishop A, Heckenberg N, Trau M, Rubinsztein-Dunlop H (2003) Mesostructured dye-doped titanium dioxide for micro-optoelectronic applications. Chem Phys Chem 4:595–603Google Scholar
  90. 90.
    Liu FM, Wang TM (2002) Surface and optical properties of films grown by radio frequency nanocrystalline anatase titania reactive magnetron sputtering. Appl Surf Sci 195:284–290Google Scholar
  91. 91.
    Oh SH, Kim DJ, Hahn SH, Kim EJ (2003) Comparison of optical and photocatalytic properties of TiO2 thin films prepared by electron-beam evaporation and sol-gel dip-coating. Mater Lett 57:4151–4155Google Scholar
  92. 92.
    Asanuma T, Matsutani T, Liu C, Mihara T, Kiuchi M (2004) Structural and optical properties of titanium dioxide films deposited by reactive magnetron sputtering in pure oxygen plasma. J Appl Phys 95:6011–6016Google Scholar
  93. 93.
    Manifacier JC, Gasiot J, Fillard JP (1976) Simple method for determination of optical-constants n, k and thickness of a weakly absorbing thin-film. J Phys E 9:1002–1004Google Scholar
  94. 94.
    Vogel R, Meredith P, Kartini I, Harvey M, Riches JD, Bishop A, Heckenberg N, Trau M, Dunlop HR (2003) Mesostructured dye-doped titanium dioxide for micro-optoelectronic applications. Chem Phys Chem 4:595–603Google Scholar
  95. 95.
    Mor GK, Carvalho MA, Varghese OK, Pishko MV, Grimes CA (2004) A room-temperature TiO2-nanotube hydrogen sensor able to self-clean photoactively from environmental contamination. J Mater Res 19:628–634Google Scholar
  96. 96.
    Yoldas BE, Partlow DP (1985) Formation of broad-band antireflective coatings on used silica for high-power laser applications. Thin Solid Films 129:1–14Google Scholar
  97. 97.
    Tauc J (1970) Absorption edge and internal electric fields in amorphous semiconductors. Mater Res Bull 5:721–729Google Scholar
  98. 98.
    Sant PA, Kamat PV (2002) Interparticle electron transfer between size-quantized CdS and TiO2 semiconductor nanoclusters. Phys Chem Chem Phys 4:198–203Google Scholar
  99. 99.
    Henglein A (1989) Small-particle research – physicochemical properties of extremely small colloidal metal and semiconductor particles. Chem Rev 89:1861–1873Google Scholar
  100. 100.
    Kokai J, Rakhshani AE (2004) Photocurrent spectroscopy of solution-grown CdS films annealed in CdCl2 vapour. J Phys D 37:1970–1975Google Scholar
  101. 101.
    Joo S, Muto I, Hara N (2008) In situ ellipsometric analysis of growth processes of anodic TiO2 nanotube films. J Electrochem Soc 155:C154–C161Google Scholar
  102. 102.
    Bruggeman DAG (1935) Calculation of various physics constants in heterogenous substances. I. Dielectricity constants and conductivity of mixed bodies from isotropic substances. Ann Phys 24:636–664Google Scholar
  103. 103.
    Stein N, Rommelfangen M, Hody V, Johann L, Lecuire JM (2002) In situ spectroscopic ellipsometric study of porous alumina film dissolution. Electrochim Acta 47:1811–1817Google Scholar
  104. 104.
    Wang J, Lin Z (2008) Freestanding TiO2 nanotube arrays with ultrahigh aspect ratio via electrochemical anodization. Chem Mater 20:1257–1261Google Scholar
  105. 105.
    Bersani D, Antonioli G, Lottici PP, Lopez T (1998) Raman study of nanosized titania prepared by sol-gel route. J Non-Cryst Solids 234:175–181Google Scholar
  106. 106.
    Tsuchiya H, Macak JM, Ghicov A, Räder AS, Taveira L, Schmuki P (2007) Characterization of electronic properties of TiO2 nanotube films. Corros Sci 49:203–210Google Scholar
  107. 107.
    Muñoz AG (2007) Semiconducting properties of self-organized TiO2 nanotubes. Electrochim Acta 52:4167–4176Google Scholar
  108. 108.
    Muñoz AG, Chen Q, Schmuki P (2007) Interfacial properties of self-organized TiO2 nanotubes studied by impedance spectroscopy. J Solid State Electrochem 11:1077–1084Google Scholar
  109. 109.
    Sato N (1998) Electrochemistry at metal and semiconductor electrodes. Elsevier, Amsterdam, The NetherlandsGoogle Scholar
  110. 110.
    Dafonseca C, Ferreira MG, Belo MD (1994) Modeling of the impedance behavior of an amorphous-semiconductor schottky-barrier in high depletion conditions –application to the study of the titanium anodic oxide electrolyte junction. Electrochim Acta 39:2197–2205Google Scholar
  111. 111.
    Oliva FY, Avalle LB, Santos E, Cámara OR (2002) Photoelectrochemical characterization of nanocrystalline TiO2 films on titanium substrates. J Photochem Photobiol A 146:175–188Google Scholar
  112. 112.
    Dolata M, Kedzierzawski P, Augustynski J (1996) Comparative impedance spectroscopy study of rutile and anatase TiO2 film electrodes. Electrochem Acta 41:1287–1293Google Scholar
  113. 113.
    Simons W, Pauwels L, Hubin A (2002) Impedance spectroscopy to characterise an anodised titanium substrate in contact with silver complexing agents: elements for an optimal parameter estimation. Electrochim Acta 47:2169–2175Google Scholar
  114. 114.
    Di Quarto F, La Mantia F, Santamaría M (2005) Physicochemical characterization of passive films on niobium by admittance and electrochemical impedance spectroscopy studies. Electrochim Acta 50:5090–5102Google Scholar
  115. 115.
    Cohen JD, Lang DV (1982) Calculation of the dynamic-response of schottky barriers with a continuous distribution of gap states. Phys Rev B 25:5321–5350Google Scholar
  116. 116.
    Boschloo GK, Goossens A, Schoonman J (1997) Photoelectrochemical study of thin anatase TiO2 films prepared by metallorganic chemical vapor deposition. J Electrochem Soc 144:1311–1317Google Scholar
  117. 117.
    Boschloo GK, Goossens A (1996) Electron trapping in porphyrin-sensitized porous nanocrystalline TiO2 electrodes. J Phys Chem 100:19489–19494Google Scholar
  118. 118.
    Redmond G, Fitzmaurice D, Grätzel M (1993) Effect of surface chelation on the energy of an intraband surface-state of a nanocrystalline TiO2 film. J Phys Chem 97:6951–6954Google Scholar
  119. 119.
    Lyon LA, Hupp JT (1999) Energetics of the nanocrystalline titanium dioxide aqueous solution interface: approximate conduction band edge variations between H–0 = −10 and H−=+26. J Phys Chem 103:4623–4628Google Scholar
  120. 120.
    Kavan L, Kratochvilova K, Grätzel M (1995) Study of nanocrystalline TiO2 (anatase) electrode in the accumulation regime. J Electroanal Chem 394:93–102Google Scholar
  121. 121.
    Gutierrez C, Salvador P (1982) Bandgap at the normal-TiO2 electrolyte interface. J Electroanal Chem 138:457–463Google Scholar
  122. 122.
    Weber MF, Schumacher LC, Dignam MJ (1982) Effect of hydrogen on the dielectric and photo-electrochemical properties of sputtered TiO2 films. J Electrochem Soc 129:2022–2028Google Scholar
  123. 123.
    Ghicov A, Tsuchiya H, Hahn R, Macak JM, Muñoz AG, Schmuki P (2006) TiO2 nanotubes: H+ insertion and strong electrochromic effects. Electrochem Commun 8:528–532Google Scholar
  124. 124.
    Fabregat-Santiago F, Barea EM, Bisquert J, Mor GK, Shankar K, Grimes CA (2008) High carrier density and capacitance in TiO2 nanotube arrays induced by electrochemical doping. J Am Chem Soc 130:11312–11316Google Scholar
  125. 125.
    Crawford GA, Chawla N, Das K, Bose S, Bandyopadhyay A (2007) Microstructure and deformation behavior of biocompatible TiO2 nanotubes on titanium substrate. Acta Biomater 3:359–367Google Scholar
  126. 126.
    Katz JL (1996) Application of materials in medicine and dentistry: orthopedic applications. In: Ratner BD, Hoffman AS, Schoen FJ, Lemons JE (eds) Biomaterials Science: An Introduction to Materials in Medicine. San Diego, Academic Press, pp 335–346Google Scholar
  127. 127.
    Park JB, Lakes RS (1992) Biomaterials: an introduction. Plenum Press, New York, pp 79–115Google Scholar
  128. 128.
    Huiskes R, Weinans H, Vanrietbergen B (1992) The relationship between stress shielding and bone-resorption around total hip stems and the effects of flexible materials. Clin Orthop Relat Res 274:124–134Google Scholar
  129. 129.
    Oliver WC, Pharr GM (1992) An improved technique for determining hardness and elastic-modulus using load and displacement sensing indentation experiments. J Mater Res 7:1564–1567Google Scholar
  130. 130.
    Tsui TY, Pharr GM (1999) Substrate effects on nanoindentation mechanical property measurement of soft films on hard substrates. J Mater Res 14:292–2301Google Scholar
  131. 131.
    Tsui TY, Vlassak J, Nix WD (1999) Indentation plastic displacement field: Part I. The case of soft films on hard substrates. J Mater Res 14:2196–2203Google Scholar
  132. 132.
    Tsui TY, Vlassak J, Nix WD (1999) Indentation plastic displacement field: Part II. The case of hard films on soft substrates. J Mater Res 14:2204–2209Google Scholar
  133. 133.
    Bahr DF, Woodcock CL, Pang M, Weaver KD, Moody NR (2003) Indentation induced film fracture in hard film–soft substrate systems. Int J Fract 119:339–349Google Scholar
  134. 134.
    Pang M, Bahr DF (2001) Thin-film fracture during nanoindentation of a titanium oxide film–titanium system. J Mater Res 16:2634–2643Google Scholar
  135. 135.
    Deng X, Cleveland C, Karcher T, Koopman M, Chawla N, Chawla KK (2005) Nanoindentation behavior of nanolayered metal–ceramic composites. J Mater Eng Perform 14:417–423Google Scholar
  136. 136.
    Deng X, Chawla N, Chawla KK, Koopman M, Chu JP (2005) Mechanical behavior of multilayered nanoscale metal–ceramic composites. Adv Eng Mater 7:1099–1108Google Scholar
  137. 137.
    Mayo MJ, Siegel RW, Narayanasamy A, Nix WD (1990) Mechanical properties of nanophase TiO2 as determined by nanoindentation. J Mater Res 5:1073–1081Google Scholar
  138. 138.
    Han Y, Hong SH, Xu KW (2002) Porous nanocrystalline titania films by plasma electrolytic oxidation. Surf Coat Tech 154:314–318Google Scholar
  139. 139.
    Fischer-Cripps AC (2004) Nanoindentation. Springer, New YorkGoogle Scholar

Copyright information

© Springer Science + Business Media, LLC 2009

Authors and Affiliations

  1. 1.Electrical Engineering DepartmentPennsylvania State UniversityUniversity ParkUSA
  2. 2.Materials Research InstitutePennsylvania State UniversityUniversity ParkUSA

Personalised recommendations